Malicious PDF — malware analysis report

Static analysis result for SHA-256 37a9bd385c3fdd70…

MALICIOUS

PDF

79.2 KB Created: 2021-09-12 14:01:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: c9ec84e0a8a4ec2f8a252f14bcb984d2 SHA-1: 5d1b68124386d75488935fb6cf6b575233115ea6 SHA-256: 37a9bd385c3fdd70f3cf629b4af95bdd50944f23685773101132d106e18cc578
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://wastran.ru/uplcv?utm_term=sudden+redness+in+eyes PDF link annotation
    • http://stellar-toys.com/ckfinder/userfiles/files/nagigokuzisebixuzitewe.pdfIn PDF document text
    • http://telekommarketing.com/firme_data/files/94012313100.pdfIn PDF document text
    • https://0924055971.com/uploads/files/202109050542072697.pdfIn PDF document text
    • http://handlpc.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/92707103021.pdfIn PDF document text
    • http://ore-processing.ru/d/files/mabatojepuzif.pdfIn PDF document text
    • https://funbugs.ie/files/file/pimikoxetefu.pdfIn PDF document text
    • https://hideab.se/tc/Mediagalleri/file/nigivilikibemiwumupizope.pdfIn PDF document text
    • https://moma-restaurant.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c9994ec9c1---69355794368.pdfIn PDF document text
    • http://hzkontejnery.cz/ckfinder/userfiles/files/gukimepixasimuze.pdfIn PDF document text
    • https://www.hadlowsecurityshutters.com/wp-content/plugins/super-forms/uploads/php/files/274ce85f5aafaa0afd517bab50b3dd4d/90002745214.pdfIn PDF document text
    • http://intranet.uts.edu.co/portal/app/ckfinder/userfiles/files/78050912607.pdfIn PDF document text
    • http://www.hkqi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135be8f1dd94---54916831989.pdfIn PDF document text
    • https://servingltda.com/userfiles/file/nenimuj.pdfIn PDF document text
    • https://muzeumkonstancina.pl/attachments/file/73944814561.pdfIn PDF document text
    • https://ciiinnovationsummit.com/ci/userfiles/files/joxejisogafote.pdfIn PDF document text
    • https://yptea.com/data/fckeditor/files/72404845737.pdfIn PDF document text
    • https://ecpa.fr/uploaded/file/mizokujabipof.pdfIn PDF document text
    • http://ejmk.com/ej/upload/files/mutibewenigoze.pdfIn PDF document text
    • http://mondoacquapiscine.com/userfiles/files/podopolegu.pdfIn PDF document text
    • http://midel.me/userfiles/file/94281928401.pdfIn PDF document text
    • https://purpleleafestatebuyers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138e1dc845bd---timifo.pdfIn PDF document text
    • http://www.bandungmesin.com/file/tifovijifiremajimomirutan.pdfIn PDF document text
    • http://foto-recepty.sk/images/fotky/bamazukuwaramubedat.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d5a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5A1 16508 bytes
SHA-256: 2ca15a1e6c52fe9f037954fb01afaef5743758bdd0536db751717150567883ff
font_01_sfnt_off0001004a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1004A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011861.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11861 10104 bytes
SHA-256: 420075ed854af37597fc73660f1597ec4d6f3fdfbf65c71d991f1a1f10210fc8